Laminated magnetostrictive transducer apparatus



July 29, 1969 R. c. HEIM 3,458,736

LAMINATED MAGNETOSTRCTIVE TRANSDUCER APPARATUS Filed March 15, 19.67

FIG.2.

WTNESSES' INVENTOR Rlchord C. Heim.

United States Patent O 3,458,736 LAMINATED MAGNETOSTRICTIVE TRANSDUCERAPPARATUS Richard C. Heim, Ellicott City, Md., assignor to WestinghouseElectric Corporation, Pittsburgh, Pa., a corporation of PennsylvaniaFiled Mar. 15, 1967, Ser. No. 623,348

Int. Cl. H04r 15/00 U.S. Cl. 310-26 2 yClaims ABSTRACT OF THE DISCLOSUREA transducer assemblage in which a plurality of thin corrugatedmagnetostrictive elements are vibratorily coupled at their one end to aradiating plate and arranged such that the laminations abut one anotherin space-separated stacks, each stack comprising two or more laminationsin which the respective corrugations nest within one another, andalternate stacks being reversed in direction for abutment of stackcorrugation ridges to obtain substantial adjacent stack separation.

BACKGROUND OF THE INVENTION Field of the z'nvention.-Magnetostrictivetransducer apparatus for ultrasonic agitation of a liquid.

Description of the prior LWL-Ultrasonic transducer apparatus in whichthin magnetostrictive laminations are bonded to a radiating plate withdistributed spacing between each lamination, as disclosed in U.S.Patents 3,161,792 and 3,173,037, are being employed with considerablesuccess in most instances; the latter patent disclosing use ofcorrugation containing laminations arranged to obtain self-spacingbetween each adjacent laminations. Under certain circumstances, such asIwhere the liquid volume being ultrasonically vibrated by the radiatingplate contains a high volume of solid material, such as workpiece partsto be cleaned in an ultrasonic bath, or where the liquid bath containsgas or air bubbles, the performances of such transducer apparatus tendsto become degraded according to the degree such conditions prevail.

SUMMARY According to the present invention improved -performance of aspaced lamination magnetostrictive transducer is obtained by a novelarrangement of the self-separating type of laminations containingcorrugations or ribs as shown in U.S. Patent 3,173,037, for examplewherein the laminations are bonded to the radiating plate in spacedapartstacks of two or more, often three, where the respective corrugations ofthe several laminations of each stack nest within one another, and theseries of stacks in a particular array alternate in direction of facingto obtain self-separation by abutment of stack corrugation ridges.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end elevation view of anexemplified 1amination array bonded to a radiating plate which is shownin cross-section; and

FIG. 2 is a fragmentary bottom view in outline of the array of FIG. 1,showing details of the array of selfspaced stacks ofcorrugation-containing laminations in accord with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, thetransducer apparatus of the present invention comprises a radiatingplate 5 for subjection to a liquid, such as a cleaning fluid, to impartvibrations thereto for cavitation as in ultrasonic cleaning of partsimmersed in such liquid, for example. Often such radiating plate willconstitute the 'bottom of a cleaning tank and at other times mayconstitute the vibratory wall of an immersible transducer disposedwithin a separate liquid-containing tank. Vibratorily coupled at theirone edge to the bottom, or, driven side, of the radiating plate 5, as byepoxy cement 7, are a plurality of thin (less than six mils, forexample) laminations 8 of magnetostrictive material (nickel, forexample) each of which is formed to`have one or more corrugations 10, orother bends, which extend along its length. On one face of eachlamination a respective corrugation represents an indentation and on theopposite face such corrugation represents a raised part or rib. Inaccord with the present invention, the laminations are ranged in groups12 of two or more, three being exemplified in the drawing, which facemutually in the same direction such that the corrugation 10 orcorrugations 10 of the several laminations of each group nest in oneanother and provide substantial abutment between such groupedlaminations, and the groups are alternated in their facing directions,wherein one group abuts another along corrugation areas that provideseparation spaces 13 between substantial portions of adjacent groups.

It is to be noted that the laminations 8 in each stack or group 12 hasbeen shown as having corresponding nested corrugations of differentsizes and with right-angled edges. This is merely by way of simplifyinga showing of such nesting. In practice, all laminations 8 may be made ofthe same shape and proportions, and nesting is readily accomplished byexerting a compressing force to opposite ends of an overall array ofsuitably arranged stacked groups 12; the yieldability of thelaminations, due to thinness and ductility, enabling suiiicientdeformation to accommodate the desired nesting.

IIn accord with the practice set forth in Patent 3,173,037, eachlamination has a pair of spaced-apart slots 15 which are aligned in eachstacked array of laminations `8 to accommodate the energizing coil (notshown herein) for such array to obtain the vibratory response of suchlaminations and hence vibration of the radiating plate 5.

I claim as my invention:

1. A transducer assemblage comprising a radiating plate for subjectionto a liquid to which vibration is to be imparted,

a plurality of thin magnetostrictive laminations each having at leastone longitudinal corrugation therein Iand each bonded at its one edge tosaid radiating plate,

said laminations being arranged in `a series of altermately-facingcorrugation-ridge abutting groups of corrugation-nested laminationshaving substantial abutment between the laminations of each group andspace separating substantial portions of each adjacent group.

2. The transducer assemblage of claim 1, wherein the laminations haveequally-proportioned respective convolutions and are made of ductilenickel less than six mils thick.

References Cited UNITED STATES PATENTS 2,391,678 12/ 1945 Bundy.2,489,768 11/1949 Firth 318--118 X 3,173,037 3/ 1965 Heim 310-26 MILTONO. HIRSHFIELD, Primary Examiner D. F. DUGGAN, Assistant Examiner U.S.Cl. X.R.

